From: Ralph Dolmans <ralph@nlnetlabs.nl>
Date: Thu, 16 Jan 2020 16:50:44 +0000 (+0100)
Subject: - improve dname_has_label(), add unit test
X-Git-Tag: release-1.10.0rc1~28^2~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bda4c4a375c20105b287c29d0b4ddef3028fe04b;p=thirdparty%2Funbound.git

- improve dname_has_label(), add unit test
---

diff --git a/testcode/unitdname.c b/testcode/unitdname.c
index 238c3edf7..b0c3fb057 100644
--- a/testcode/unitdname.c
+++ b/testcode/unitdname.c
@@ -794,6 +794,33 @@ dname_test_valid(void)
 		, 4096) == 0);
 }
 
+/** Test dname_has_label */
+static void
+dname_test_has_label(void)
+{
+	unit_show_func("util/data/dname.c", "dname_has_label");
+	/* label past root label */
+	unit_assert(dname_has_label((uint8_t*)"\01a\0\01c", 5, (uint8_t*)"\01c") == 0);
+	/* label not found */
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c\0", 6, (uint8_t*)"\01e") == 0);
+	/* buffer too short */
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c\0", 5, (uint8_t*)"\0") == 0);
+	unit_assert(dname_has_label((uint8_t*)"\1a\0", 2, (uint8_t*)"\0") == 0);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c", 4, (uint8_t*)"\01c") == 0);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\03qwe\06oqieur\03def\01c\0", 19, (uint8_t*)"\01c") == 0);
+
+	/* positive cases  */
+	unit_assert(dname_has_label((uint8_t*)"\0", 1, (uint8_t*)"\0") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\1a\0", 3, (uint8_t*)"\0") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\01a\0\01c", 5, (uint8_t*)"\0") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c", 5, (uint8_t*)"\01c") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c\0", 10, (uint8_t*)"\0") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\01c\0", 7, (uint8_t*)"\0") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\03qwe\06oqieur\03def\01c\0", 22, (uint8_t*)"\03def") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\03qwe\06oqieur\03def\01c\0", 22, (uint8_t*)"\02ab") == 1);
+	unit_assert(dname_has_label((uint8_t*)"\02ab\03qwe\06oqieur\03def\01c\0", 22, (uint8_t*)"\01c") == 1);
+}
+
 /** test pkt_dname_tolower */
 static void
 dname_test_pdtl(sldns_buffer* loopbuf, sldns_buffer* boundbuf)
@@ -855,6 +882,7 @@ void dname_test(void)
 	dname_test_canoncmp();
 	dname_test_topdomain();
 	dname_test_valid();
+	dname_test_has_label();
 	sldns_buffer_free(buff);
 	sldns_buffer_free(loopbuf);
 	sldns_buffer_free(boundbuf);
diff --git a/util/data/dname.c b/util/data/dname.c
index 10da71f6b..239a56ac1 100644
--- a/util/data/dname.c
+++ b/util/data/dname.c
@@ -562,12 +562,20 @@ int
 dname_has_label(uint8_t* dname, size_t dnamelen, uint8_t* label)
 {
 	size_t len = *dname;
-	while(*dname && len <= dnamelen) {
-		if(*dname == *label && memlowercmp(dname+1, label+1, *dname) == 0)
+	while(len <= dnamelen) {
+		if(!(*dname)) {
+			if(*dname == *label)
+				return 1; /* empty label match */
+			/* termination label found, stop iterating */
+			return 0;
+		}
+		if(*dname == *label && *label &&
+			memlowercmp(dname+1, label+1, *dname) == 0)
 			return 1;
 		len += *dname;
 		dname += *dname;
 		dname++;
+		len++;
 	}
 	return 0;
 }